IBAN Validator
Enter an IBAN number to check whether it is valid and get a full breakdown.
Spaces are ignored automatically. You can paste the IBAN with or without spaces.
What is an IBAN and how does it work?
The IBAN (International Bank Account Number) is an international standard for identifying bank accounts, defined by ISO 13616. It allows transfers between countries in a standardised way and with a lower risk of errors.
IBAN structure
| Part | Length | Example (GB) | Description |
|---|---|---|---|
| Country code | 2 letters | GB | ISO country code |
| Check digits | 2 numbers | 29 | Verify the IBAN is valid |
| BBAN | Variable | NWBK 6016 1331 9268 19 | Domestic account number |
IBAN length by country
| Country | Code | Length |
|---|---|---|
| United Kingdom | GB | 22 |
| Germany | DE | 22 |
| France | FR | 27 |
| Spain | ES | 24 |
| Italy | IT | 27 |
| Portugal | PT | 25 |
| Netherlands | NL | 18 |
How is an IBAN validated?
The MOD-97 validation algorithm works as follows:
- The first four characters are moved to the end of the IBAN.
- All letters are converted to numbers (A=10, B=11, ... Z=35).
- The resulting number is divided by 97.
- If the remainder is 1, the IBAN is valid.
Frequently asked questions about IBAN
What is an IBAN?
An internationally agreed standard that uniquely identifies a bank account. It consists of a country code, two check digits and the domestic account number.
How many digits does a UK IBAN have?
22 characters: GB + 2 check digits + 18 digits (sort code and account number).
How is an IBAN validated?
Using the MOD-97 algorithm: the IBAN is rearranged, letters are converted to numbers and the result modulo 97 must equal 1.
Is an IBAN the same as an account number?
No. The account number is the domestic part. The IBAN adds the country code and check digits to allow standardised international transfers.